Accor, a major hotel group, has agreed to tackle child prostitution in its hotels in Asia.
Bangkok is one of Asia's top tourist destinations
Starting in Thailand, Accor staff will be trained how to spot child sex workers in their hotels, and what to do when they have suspicions about guests.
Accor has signed up to a code of conduct drafted by ECPAT, an international group which is trying to stamp out the sexual exploitation of children.
According to ECPAT, there are thought to be as many as 200,000 children involved in Thailand's sex trade.
Helen Veach, co-ordinator for ECPAT in the UK, told BBC News Online that the Accor campaign is part of a wider campaign to get the tourism industry involved in the fight against the child sex trade.
"When we first started campaigning on this issue, there were a lot of barriers in the tourism industry. But now concrete things are happening and Accor in Thailand is really leading the rest," she said.
She said that simple measures, like displaying posters in hotel lobbies and reminding staff how to raise suspicions with their managers, would form part of the campaign.
Sendrine Fabiem, ECPAT's international tourism co-ordinator, said that there were many misconceptions surrounding child sex tourism.
"The awareness part of the training tells the staff what is the issue, who are the offenders. Very often we think of the offender as an old German guy- but it could be anybody, and it is mostly locals, mostly Asians," she told the AFP news agency.
Accor operates 89 hotels across 12 Asian countries, and has promised to extend the training scheme to other countries in the region.